Improvement in wood-saw frames



E. W. BATES. WOODSAW FRAME.

No. 37.999. Patented Mar. 24, 1863. g

UNITED STATES PATENT OFFICE.

EBASTUS W. BATES, or 'WATERVILLE, MAINE, assrenoa r0 JOHN ELLIS, on nonrn BRIDGEWATER, MASSACHUSETTS.

IMPROVEMENT IN WOOD-SAW FRAMES.

Specification forming part of Letters Patent No'. 37,999, dated March 24, 1863.

To all whom it may concern:

Be it known that I, ERASTUS W. BATES, of \Vaterville, in the county of Kennebec and State of Maine, have invented certain 11nprovements in the Frames of Wood-Saws, of which the following is a full, clear, and exact description, reference being had to the acccmpanying drawings, making part of this specification, in which- 1 Figure 1 is a perspective view of a wood- ;saw with my improvements attaehr d thereto; gFig. 2,-an elevation of part of the frame, with the partsin another position. My invention consists in an improved me- .-chanical device for drawing up the top part of t-he'frame of a wood-saw to strain the sawblade.

That others skilled in the art may undtrstand and use my invention, 1 will proceed to describe the manner in which I have carried it out.

In the said drawings, A is the saw-blade, B B the two end bars or handles, 0 the middle brace, and I) the top brace. The saw is secured to the bars B B in the usual manner by a pin, (1,213 each end. The brace O is simply mortised into the-bars. The brace D is pinned to the bar B at one end, at c, and the tenon at the opposite end is cut down at its shoulders, to allow the top of the bar B to be drawn in toward the bar B. This is done by the following device: A double strap, E, is pivoted at-d to the brace D. It falls over the head of the bar B, and has pivoted to its outer end a hand-lever, G,'the butt of which forms a-cam,.f. A plate, I, is attached to theouter end of thebar B, near its top, for the cam f to bear against. Small indentations i are made in the plate I, to prevent the cam from slipping or being knocked out. of place. When the lever G is turned up into the position shown in Fig. 2, the strap E may be raised or lowered, or lifted entirely'over; the head of the bar B. When the lever is turned down, as in Fig. 1, the cam f bears against the bar B and draws its top toward the bar B. The sta tionary brace 0 being a fulcrum, a strain is thus brought on the saw-blade A. As the strap E is brought down nearer to a line with the brace'D, this strain is increased.

I am awarethata pawl and inclined ratchet has been applied to the lower end of the bar B and the saw-blade to secure the blade in different positions in the frame, with more or less strain on the blade, as shown in the patent of James Haynes, August 9, 1859;but itis much preferable to have no device of this kind attached to the lower end of the frame, where it is liable to strike the ground when being used, and be broken or knocked loose. I am also aware that an eccentric or cam has been applied to the saw-blade to strain it; but the same objection above stated applied to the position which itoccupied. I am also aware that an eccentric on a lever has been applied to a rod .to draw the top of the frame together, and thus to strain the saw; but the rod being attached directly to the eccentric, required to have the position of the eccentric on' the rod changed, to vary the amount of strain which could be applied to'the saw.

What 1 claim as my invention, and desire to secure by Letters Patent, 'isv .The combination of the strap E, pivoted to the brace D, the lever G, with its cam j,

pivoted to'the strap, and the plate. I, with its indentation i, applied to the head of the bar B, in the manner specified. f

' ERASTUS W. BATES. Attest:

E. R. Dammonn, JOHN S. GmnLEn. 

